Gauze or screen catalyst holder or support



July 14, 1931. s. L. HANDFORTH GAUZE .OR SCREEN CATALYST HOLDER OR SUPPORT Filed July 12, 1929 [n venlo, Handfor, By hzls avorne Patented July 14,1931

f UNITED STATES APATENT OFFICE..

STANIJES L. HANDEORTH, OF WOODBURY NEW JERSEY, ASSIGNOR TO E. I. DU PONT` DE I NEMOURS & COMPANY,

WARE

p GAUZE onsonEnN cATALvsT HoLnER'on" SUPPORT' Application filed J'ulyk12, 1929. Serial No. 377,666.

This invention relates to a holder or support for a catalyst and more particularly to a holder or support for the contact, or catalyst, screen orgauze used in ammonia oxivla, dation apparatus of the general broad type disclosed in'U. S. Patent 1,321,876, to Jones and Parsons, November 11, 1919.

In the type of apparatus disclosed by Jones up) `and Parsons a catalyst screen is placed With- {f'io 1n a converter chamber and ammonia and air are passed into the chamber and, upon contact with the catalyst, the ammonia is oxidized into oxides of nitrogen. The present invention, while not restricted thereto, has

Lm"i5 particular application to holders or supports 'for such screens.

In the practice of the Jones and Parsons process, the screen and its holder are subjected to a high temperature with resulting 920 rapid deterioration of the llOldeI if mil-Cle 0f the ordinary materials. Also most metals at -this elevated temperature act catalytically Y on a vmixture of ammonia and air and cause oxidation of ammonia to free nitrogenwlth ffas resulting loss in yield ofthe final product.

There is thefurther disadvantage that the gauze or screen at thiselevated temperature is so weak that the strain caused by the gas passing through it is suflicient to cause rupf-'o ture unless special precautions .are taken to support the gauze andreduce this strain. According lto my invention a holder of such character has been devised1 that these disadvantages are substantially'overcome.

Aniobject of this inventionis a holder or support for a screen or for th'ecatalyst suit- Yappear as the description proceeds.

These objects are accomplished by the following invention in which 'l vhave found that [and silica linings 7 a-nd 8. The screen in the a catalyst supportor holder constructed of i' certain new alloys will withstand theconditions of operation in the oxidation of gases without deterioration.` Furthermore when such a holder'is constructed so'as to support the cylindrical gauze or screen at both ends and at a suiiicientnumber of pointsfalong the sides of the cylinder, the-strain on the catalyst itself under the yconditions ,of operation may be relieved. Also, vI have found that when all metal elements of the 'support arb placed out of the stream of the gases'to be oxidized that greater yieldof the, desired products results.

Y lThe following example is illustrative of one form of my invention as applied to the, oxidation of ammonia-air gases,.but,it will 'be apparent that other modifications` exist, and

may be practiced, and that my invention may be applicable to the handlingof other gases or mixtures. 'K s In the accompanying drawings'Figure lS a sectional plan view of the assembly embodying the invention. Figure 2 is a vertical diametrical section of the same showingthc. method of assembling'the supporting cage.

`Referring' now to Figure 2, theapparatus in general comprises a lcatalyst screen 4.',screen holder 5,1clamping and supporting cage,

case of ammonia oxidation is preferably of platinum alloy gauze' or equivalent thereof, cylindrical in shape and formedof any'desired number of layers? of material. In' operation, a. suitable mixture of air and amoF WILMINGTON, DELAWARE, a CORPORATION oF DELA# monia is introducedl into the interior of the screen 4, and in passing through the screen the ammonia is converted into oxides of nitrogen. The holder 5 comprises the depending, supportingcylindrical shell'or sleeve 9 hav- ,ing the flange 10 adapted to be bolted to the top of the oxidation chamber (not shown) or between the flanges of the inletpipe and the chamber; The periphery of the lower rim 11 of the shell 9 is formed with a slight bead on its outer edge as indicated at 11 inFi'gur'e 2.

.Also, studs 12 on the outer surface-of the shell are provided near the lower end. y TheV supporting cage 6 is composed-of anuppejrring l5 and. a, lowerrlng lQQgnpgtggfl by yepiggl, M,

rods 14. The upper ring of the cage is grooved so as to mate with the bead on the supporting shell 9 as shown. Holes are also provided 1n this ring to mate With studs 5 12. The gauze or screen is then held between .'ihe diend l'and *groove Aas Shown 1in the drawings. *The -lower ring of the cage l-is `grooved so as to mate with the edge o'fplate L5 which @loses .theend of the cage and also the gauze .or screen. `The rings or" the Ycage are oiiited "by tongue and groove joints so that the cage.niaybe separated in two or more vertica1`sect`ions'to 'facilitate its being removed and for =con-venience 1ct rassembly on the sleeve.

'Ihrnugh `,the :tongue and groove fj oint as showin sin iFigufreQ there is a tapered slot E6 though 'which a it'apered wedge "117 :is :inseiitedrtordrawthe rings ofzthe cage up itighti'qnthersuppurtingfsleevezand ibottom iplate, i* hue damping .the whole .assembly itogether wird ',atening fthe gauze lfirmly 1 at both i ends. @It aviilibempparentithatall 5.but one of these ijoi'lliisin each-maybe made as La hinge Q5 ljnint'wirthont altering .the operation .of .the hplder, fand itlalt similar .modifications are eviitflin itlie. pin-view nf :my 4iinvention. The ipihs .12 am shell 1,9 snpportitheieage and etfectively prevent its separating 'ifrornthel'oyll'mdrical fshjell; :Rods 11A 'fibe'sides eonnecting the lnweriring Yitoethe burly fof :the holder .also @Ruppert the cylindrical :gauze :from being fonce'd .out Internity i-hy theeut'flewing ases. lIhiesveritionsar'e'spreferdbly faetenejd together iby the wedging means .fas lshown. iLugs Y and bolts may be used in pl ace1ofithese,but, .due to the fhigh @temperature 'to "which these .ele- -ments Jane isubjeted, -belts are dften .unsatsctony; zlsio, there :is :often not suflicient ie'faiel-forbol'tsrat this 'ipoint lihe :suppoitingrcylindrical 'shell-9 may .he anni spreteraicl-.y Yis further rlined with ra nonietalli'c .inneiwsle'eve 'er lining .which prevents l-cont'a'ct @qt the :incominglugas stream @l5 wlth the ih'ot metal surfaces of fthe shell 9. :This 'inlay Shave on aits .upper -end ia lange '.18 -fonwhifchiitihangs andasbestosor other suitable material 219 lfmay .he laid underithe Ledge of this flange it'o prevent itlie `gas 'passing be- '560 tween the lirii'ng and t'he supporting sleeve.

With a )lining inf this` type'the temperature ftf the riirfavce ii-'n Contact with `the incoming gas is luppreciafb'ly lower Ythanithat lof labare supporliin'gsleeve which greatly ireduces ithe vdanger"foif zloss vof #ammonia on t-his fsunace. ilfhe eplte 15 folosingthe ibottom @of the :cylin` der isfcovered byfaaienfinetallicplate 8. ffii-usY -heineominjgbgasistre ain isientirely prevented ifa-onl comingiin contact witlphot metalsur- W0 fac'es hright r cause lo'ssoflammonia.

While three sectionsdfthe suppontor cage a1e'1-preterabl'e, it will be 'apparent 'that two "ergevenmore tlran 'three vsections may lbe pro- 'i ded Within the Iseop'e vor 'my invention. 565 uets'erillnot Withstan'dlthefcondyibeing;resistantitoithe-corrosive conditions and having only very slight deleterious catalytic Aaction can lbe used .advantageously for sup- :porfin g other rtypes di' catalysts such ias ibase -rnetal oxid'ei'cataliyst.

Thile a .cylindrical :holder vhas been .-par ticularly described to accommodate :a icylin- Vdifical .screen iorgauze, :it will, of course, Vbe understood that holdersorfsupports ofiothel Vshapes may be iused ifidesired to correspond to .the design: or A'shape y of thefscreeni or gauze selected. Y

ns :many apparently widely idilierentaem- -bodinients not athis Vinvention may ibe 'made .W-ithout departing fromfthe :spirit thereof, it :is to rbe understood :that f I do 'not limit-mtysslf :to .the =foregoingiexamplesor description except as indicated in the following'claims:

i1. in a fscreenhdlder, .in nombination, 'a sleeve z or shell, :and .a :clamping :and support- Bing cage :for ithesoreen, iadapted '.at iits upper edge to engage itheloWer edge of'the. sleeveior Yshell.

12. In 2a screen holder, in icoinbination, fa sleeve or shell hauing L.supptnfting ime'ans ent yone end and engaging v'means at the otherf end, and 4a clampingjand supporting cage -havi-ng :a grooved ringaround 'its 'upperedg'e adapted to engage V'theengaging means-and -the edge of ithe* screen to Ebe supported thereby. Y i

3. .The apparatus 'of claim 1 Ein ivhirih themetallic 'elements comprise an alloy of at least '60 per cent Vnickel .and 'at Lleast `1T) per centichromium.

11. The apparatus L c'laim 2 in .which the metallic elements V.comprise an alloy yof :21pproximately S0 per 'cent nickel and 20 per cent chromium.

Y5. In a screen holder, in combination, a sleeve or shell having supporting means at one end and engaging means at the other, .of :a clamping and supporting cage vcomprising .rings adapted to engage and 'support zthe sc-reen, one of the ringsfalso -adapted .to m5 engage ,the 'rsleeve or-shel1, a-nd :spacing niem- 'bers .connecting theirings.

6. In Aa .screen iholderand support, inecombinatomalsleeve onshellahavingsupporting Queens .at ione :enwd mnd fa ibead int theethar, a W0 clamping and supporting cage for the screen and adapted to engage the bead.

7 In a screen holder and support, in combination, a sleeve or shellhaving supporting means at one end and a bead at the other, a clamping and supporting cage for the screen and adapted to engage the bead, and studs on y the shell for engaging and supporting the ring.

8. In a screen holder and support, in combination, a sleeve or shell, a clamping and supporting cage for the screen and a plate closing the outer end of the cage member.

9. In a screen holder and support, in combination, a sleeve o* shell adapted to be connected to an oxidation chamber a non-metallic inner sleeve for the shell, abead surrounding the lower edge of the shell, a cage Jfor supporting the screen and adapted to engage the upper edge of the screen and the bead, the cage having a closing plate at its outer end and a non-metallic lining for the closing plate.

l0. In a screen holder and support, in combination, a sleeve or shell adapted to be connected to an oxidation chamber, a non-nietallic inner sleeve for the shell, spaced studs on the shell, a cage for supporting the screen and comprising at least two sections, holes in the upper edge of the sections for engaging the studs and adapted to support the cage, a bead surrounding the lower edge of the shell and adapted to engage the upper edge of the screen the caOe havin a closinfr late at its 7 b 2D p Y outer end.

11. A screen support in the form of a cage adapted to be separated therefrom, the end members of the cage adapted to clamp the screen or gauze to the supporting means and spacing members connecting the end and adapted to support the screen.

12. A gauze or screen holder or support comprising a cylindrical cage adapted to be separated into at least two sections for convenience in assembly, and *adapted when assembled to enclose a cylindrical gauzev or screen and engage a supporting means at one end, and a closing plate at the other end.

13. A gauze lor screen holder and support, in combination, a cylindrical cage comprising two rings separable into at least two parts, one ring adapted to mate with and engage a bead and supporting stud of a cylindrical open ended supporting shell, and another ring adapted to mate Vwith and. engage a closing plate, the rings also adapted to enclose and engage a cylindrical gauze, spacing members connecting the two rings and supporting the rings and plate and the cylindrical screen.

In testimony whereof, I aliiX my signature.

STANLEY L. HANDFORTH. 

